Tool-less quick locking screw nut

ABSTRACT

A tool-less quick locking screw nut is secured onto a connecting object having a male thread and includes a pull-ring tab and an axle portion secured to an axle portion of the connecting object. The axle portion has a passage with a female thread, such that the pull-ring tab rotates the screw nut into or out of the connecting object without using a tool. The screw nut further includes two spacers, and the clamping force of the two spacers press the pull-ring tab onto a clamping plate, so that if the pull-ring tab is lifted, a user can hold and turn the pull-ring tab to secure/remove the screw nut to/from the connecting object. The pull-ring tab can be turned parallel to the clamping plate and securely attached to the clamping plate to prevent the connecting object from being shaken by a high-speed rotation of the object.

FIELD OF THE INVENTION

The present invention relates to a locking screw nut, and more particularly to a locking screw that can be secured or removed quickly without using a tool.

BACKGROUND OF THE INVENTION

A vast majority of assembled electric tools, particularly the rotary grinding tools can be replaced by general pneumatic tools, which feature the power-saving and easy-to-operate advantages, and thus become popular and used extensively. The common pneumatic tools include pneumatic grinding tools and pneumatic polishing tools, and the theory of pneumatics for these pneumatic tools uses a compressed air as the motive force to convert the energy stored in the compressed air into the mechanical energy for the manufacture, wherein a pneumatic motor installed in the pneumatic grinding tool to drive an axle of the pneumatic grinding tool to rotate, so as to drive the grinding object installed at the end of the axle to rotate and achieve the manufacture with a grinding and polishing effect. After the grinding and polishing made by the grinding tool, any flaw or rust on the work piece can be removed to produce a flat and bright surface.

Referring to FIG. 1 for the schematic view of a prior art, the prior art pneumatic grinding tool 30 secures a grinding object 302 to a main shaft 303 of the pneumatic grinding tool 30 by a screw nut 301, and the screw nut 301 has a convenient feature of releasing and locking the grinding object onto the pneumatic grinding tool 30.

However, if it is necessary to replace a worn-out grinding object 302 from the pneumatic grinding tool 30, then a removing tool (such as a wrench) must be used to secure/loosen the screw nut 301, and a general user usually needs to use two or more wrenches for the removal, wherein a wrench 31 is mounted onto the pneumatic grinding tool 30 as a support point, and another wrench 32 is placed on the screw nut 301 and rotate with respect to the screw nut 301 as a force applying point, so at to remove the screw nut 301 and achieve the effect of replacing the grinding object 302. From the measure taken above, it is obvious that the assembling and removing procedures are complicated and laborious.

On the other hand, the wrenches 31, 32 are used only when it is necessary to install/remove the grinding object 302 onto/from the pneumatic grinding tool 30, and the wrenches 31, 32 are not integrally installed to the pneumatic grinding tool 30, and thus the wrenches 31, 32 may be placed anywhere or the wrenches 31, 32 may even be missing easily. If a user needs to replace a grinding object 302 immediately, the user may not be able to find the wrenches 31, 32.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to overcome the foregoing shortcomings and avoid the existing deficiencies by providing a tool-less quick locking screw nut to be secured onto a connecting object (such as a pneumatic grinding tool) having a screw thread to substitute the foregoing wrench, wherein the quick locking screw nut includes a base having a circular through hole, a circular plate disposed between the rim of the base and the through hole, and the circular plate includes a plurality of grooves, and the base includes a spacer attached onto a surface of the circular plate and having an external radius smaller than the external radius of the circular plate. Further, the spacer at another surface of the base includes a clamping plate, and the clamping plate includes a group of corresponding grooves, a screw head having an axle portion extended from the screw head and coupled to the connecting object, and the axle portion includes a passage with a female thread, and the axle portion uses another spacer to press a pull-ring tab installed in the groove, and the screw head uses the axle portion to pass through and is riveted to the clamping plate and the base. It is worth to point out that the pull-ring tab can turn the quick locking screw nut into or out from the connecting object without using any removing tool (such as a wrench 32). By turning the pull-ring tab, another connecting object (such as a grinding obeject) can be secured to or removed from the connecting object to achieve the purpose of replacing the grinding object.

On the other hand, the installed quick locking screw nut and the axial protrusion of the pull-ring tab are accommodated in the groove to press onto the circular plate of the base and limited vertically by the two spacers. In such design, the pulling-ring tab and the clamping plate can be securely attached when the connecting object (such as a pneumatic grinding tool) is turned on, so as to prevent the connecting object (such as a grinding object) from being shaken by the high-speed rotations that adversely affects the grinding job.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a prior art;

FIG. 2 is a schematic view of a preferred embodiment of the present invention;

FIG. 3 is an exploded view of a preferred embodiment of the present invention; and

FIGS. 4A, 4B, and 4C are schematic views of the movements of a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The technical contents of a tool-less locking screw nut used for locking a threaded connecting object in accordance with the present invention will now be described in more detail hereinafter with reference to the accompanying drawings as follows:

Referring to FIG. 2 for the schematic view of a preferred embodiment of the present invention, the present invention can be used to secure at least one grinding object 11 onto a main shaft 10 of a pneumatic grinding tool 1 and the invention includes a quick locking screw nut 2, and the quick locking screw nut 2 includes an axle portion 201 secured to the main shaft 10, and the axle portion 201 includes a passage 21 with a female thread 211. Further, the quick locking screw nut 2 also includes a pull-ring tab 23.

Referring to FIG. 3 for the exploded view of a preferred embodiment of the present invention, the main shaft 10 includes a male thread 101 for engaging with the quick locking screw nut 2, and the quick locking screw nut 2 further comprises a screw head 20, two spacers 22, 25, a clamping plate 24, a circular plate 27, and a base 26, wherein the base 26 and the circular plate 27 are stacked with each other, and the circular plate 27 includes a plurality of grooves 271, and one surface of a circular plate 27 disposed on the base 26 is attached onto a spacer 25 which has an external radius smaller than the external radius of the circular plate 27, and the spacer 25 could be a leaf spring. Further, another surface of the base 26 opposite to the spacer 25 is coupled to the clamping plate 24, and the clamping plate 24 includes a group of corresponding grooves 241. The axle portion 201 is disposed on the screw head 20 for pressing an axial protrusion 231 of a pull-ring tab 23 by another spacer 22 (which could be a leaf spring), such that the axial protrusion 231 is limited in the groove 241 and passed through the groove 241 to press the spacer 25, and the screw head 20 uses the axle portion 201 to pass through the spacer 22, the clamping plate 24, the circular plate 27 and the base 26 in sequence and is integrally riveted to the clamping plate 24 and the base 26, and thus the pull-ring tab 23 can be disposed securely and vertically on the clamping plate 24 or attached onto the clamping plate 24.

It is worth to point out that the axial protrusion 231 of the pull-ring tab 23 is accommodated in the groove 241 and presses the circular plate 27 of the base 26, after the quick locking screw nut 2 is installed. Further, the two corresponding spacers 22, 25 are used to limit the pull-ring tab 23 onto the clamping plate 24, so that when the pneumatic grinding tool 1 uses the pneumatic motor (not shown in the figure) for providing a motive force to drive the grinding object 11 to rotate, the pull-ring tab 23 is at a status parallel to the clamping plate 24, and the axial protrusion 231 of the pull-ring tab 23 is limited vertically on the spacer 22, 25, such that the pull-ring tab 23 and the clamping plate 24 are attached securely to prevent the grinding object 11 from being shaken by high-speed rotations.

Referring to FIGS. 4A, 4B, and 4C for the schematic views of the movements of a preferred embodiment of the present invention, a female thread 211 on the passage 21 is used to screw the quick locking screw nut 2 onto the main shaft 10 of the pneumatic grinding tool 1, and users can use the pull-ring tab 23 to turn and lock the grinding object 11 onto the pneumatic grinding tool 1, or the user can lift the pull-ring tab 23 of the quick locking screw nut 2. Now, the pull-ring tab 23 is perpendicular to the grinding object 11, and the axial protrusion 231 of the pull-ring tab 23 is also limited vertically on the spacer 22, 25. The user further turns the pull-ring tab 23 to remove the grinding object 11 from the pneumatic grinding tool 1. In the description above, the pull-ring tab 23 of the quick locking screw nut 2 is used to achieve the quick locking and removing effects without using an additional removing tool.

In summation of the description above, the movements of the pull-ring tab 23 leverage a resilient property of the groove 271 to provide a shock absorbing effect when the axial protrusion 231 is limited by the circular plate 27, so as to prevent the axial protrusion 231 from being deformed.

While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures. 

1. A tool-less quick locking screw nut, provided for locking a connecting object having a male thread, and said quick locking screw nut comprising: a base, having a circular through hole, a circular plate disposed between the rim of said base and said through hole, and a spacer attached on a surface of said base having said circular plate, and the external radius of said spacer being smaller than the external radius of said circular plate; a clamping plate, coupled to another surface of said base corresponding to said spacer, and said clamping plate having a group of corresponding grooves; a screw head, having an axle portion extended from said screw head and secured to said connecting object, and said axle portion having a passage with a female thread, and said axle portion using another spacer to press a pull-ring tab installed in said groove, and said screw head using said axle portion to be passed through said spacer, said clamping plate, said circular plate, and said base in sequence and riveted to said clamping plate and said base as a whole, such that said pull-ring tab is securely and vertically disposed on said clamping plate or attached onto said clamping plate.
 2. The tool-less quick locking screw nut of claim 1, wherein said pull-ring tab includes a group of corresponding axial protrusions.
 3. The tool-less quick locking screw nut of claim 1, wherein said spacer is a leaf spring.
 4. The tool-less quick locking screw nut of claim 1, wherein said circular plate includes a plurality of grooves. 